ESRB certificates for Metal Slug X and Front Mission 3 indicate both titles will be released as PSOne Classics sometime soon.

Both titles got ratings of T-for-Teen, for violence. Examiner, which spied the listings first, notes that Front Mission 3 was re-released on the Japanese and European PlayStation Stores in March 2009 and September of this year, respectively.

Metal Slug X, a 2001 game for the PSOne, features more content and improved graphics over Metal Slug 2.